Drill bit



July 6, 1937. F, A AHE 2,086,397

DRILL BIT Filed June 22, 1935 EH4 Tia/a Q/d Patented July 6, 1937 DRILLBIT v Fer-i A. 'l'halieid, Dallas, Tex assignor to The Guiberson rationof Delaware Corporation, Dallas, Tex" a 60m- Application June 22. 1935,Serial No. zuzc and useful imimproved drill bit which may be readilyassem- 5 bled or dis-assembled and which carries the usual conicalcutters and is particularly adapted for use in drilling in hardformation during well drilling, or the like.

An important object of the invention is to provide an improved mountingfor the conical cutters of a drill bit which provides an increased areafor bearing the thrust against said cutters occasioned by the drillingoperation, whereby the life of the drill is increased.

A further object of the invention is to provldean improved drill bithaving conical cutters mounted thereon, the mounting including elongatedrollers on which the cutters are rotatable, whereby an increased bearingsurface for each 20 cutter is provided. I

A still further object of the invention is to provide an improved drillbit having conical cutters and including a split body having the cuttershafts carried at its lower end, the split body 25 permitting the easydis-assembling of the bit toremove or replace cutters when worn, or forany other reason.

, A construction .designed to carry out the invention will behereinafter described, together '30 with other featm'es of theinvention. I

The invention will be more readily understood from a reading of thefollowing specification and by reference to the accompanying drawing. inwhich an example of the invention is shown, and

'35 wherein:

Figure l is a view partly in elevation andpartly in section of a drillbit constructed in accordance with the invention,

f Figure 2 is a horizontal, cross sectional view, 40 taken on the line2-2 of Figure l, and,

Figure 3 is a transverse, sectional view, taken on the line 3-3 ofFigure 1.

In the drawing, the numeral iii designates a split body includingcomplementary sections or 45 halves A and B. Each section issemi-circular in cross section, whereby when placed together a circulardrill bit body or head having a vertical bore ll extending therethrough,is formed. The upper end of the body is provided with a reduced, 50tapered pin i2 which is threaded to receive the drill stem. Since thepin is smaller in diameter than the body, an outwardly directed shoulderI3 surrounds the lower end of said pin. It is pointed out that the pincould be eliminated and 55 any other suitable drill stem connectionsubstituted therefor. For securing the sections A and 3 together,

the lower end of the bore ll of the body is provided with an annular,depending flange ll. The

60 outer end of the flange is beveled at I! as is 4 Claims. (C 255-11)shown in Figure 1. The upper end of the bore is provided with a similarflange I6. An elongated tubular connecting sleeve ll extends through thebore ii and has an enlarged collar i8 'onits lower end. This collar hasan internal annular groove is which is arranged to be engaged by theannular flange It at the lower end of the bore. The groove has one facebeveled complementary to the bevel ii of said flange.

The upper end of the connecting sleeve extends upwardly above the upperend of the bore and is screw-threaded to receive a collar 20. The

collar is provided with an annular groove 20'.

in its under side and when said collar is tightened down, said groove isengaged by the annular beveled flange l8 at the upper end of the bore.

It will be seen by observing Figure 1, that when the connecting sleeveis passed through the bore II as shown, and the collar 20 screwed ontoits upper end, the two sections A and B will be securely clampedtogether by the collars l8 and 20 engaging the annular flanges l4 andIt. It is noted that the complementary bevels of the flanges and groovesin said collars serve to draw the sections together, whereby a tightconnection therebetween is provided. The engaging faces of the sectionsmay be machined so that a.

fluid tight joint is had therebetween. Each section is formed with adepending leg or hanger 2| and when the sections are secured togetherthe hangers are' located, diametrically opposite each other. Since thehangers are constructed exactly alike a description of one will sumce.As is obvious by observing Figure 1, each hanger has its inner face 2|inclined upwardly toward the center of the body. This inner face is flatand substantially circular in cross section, being provided with anaxial opening ,22. Each hanger has the conical cutter 23 mounted thereonand. this mounting is one of the features of the invention.

Each cutter is provided with an axial bore 24 which extends partiallythrough said cutter from the base thereof and this bore is provided withan annular recess 25 in its side wall. The axle 26 on which the cutteris mounted is made separate from the hanger 2| and has an external,annular flange 21 formed thereon. An axial recess 28 is located in theface 2| of the hanger and this recess is of the same diameter as theadjacent upper end portion of the axle 26, whereby said upper endportion of the axle flts therein.

The depth of .the recess is such that when the upper end of the axle isengaging the inner end of said recess, the annular flange 21 of the axleis abutting the face 2| of the hanger (Fig. 1).

For holding each cutter on the axle and also for fastening the axle tothe hanger a headed pin it is provided. The pin has its head 2! fittingrather snugly the bottom of the bore 24 of the cutter and has its shank30 extending upwardly through an axial bore 26' in said axle and throughthe opening 22 in the hanger. The upper end of the shank is welded at30' to the outer face of the hanger. The lower end of the axleis reducedat 3| to form an internal annular shoulder 32, and when the cutter is onthe axle, this reduced lower end registers with the annular recess 25 inthe wall of the bore, the shoulder 32 being opposite the upper end ofsaid recess.

Elongated rollers 33 are located within the raceway produced by therecess 25 and the reduced portion 3| of the axle, whereby the conecutter is readily rotatable on the axle. The rollers carry the loadimposed on the cutter during operation. It is pointed out that the head29' of the pin 29 is of a larger diameter than the reduced lower end ofthe axle, whereby said head serves to prevent the rollers from'movingdownwardly out of the annular recess 25. The shoulder 32, of course,prevents their upward movement. It is obvious that with the abovestructure the pin not only serves to secure the cutter to the axle butalso fastens said axle to the hanger.

In assembling the device, the cutters and axles are first secured to thehangers of each section. This is accomplished by positioning the head 29of the pin in the bottom of the bore and then placing the elongatedrollers 33 within-the annular recess 25 of the bore. The-axle is thenslid down over the shank 30 of the pin, into position within the bore.The upper portion of the shank is then entered into the axial opening 22in the hanger and welded therein at its upper end.

After each section has been assembled as above, the two sections arethen placed around the connecting sleeve l1 and secured together as hasbeen described. The assembling and disassembling is accomplished quicklyand easily. There are a minimum of parts and by making the body In insections, it is not only easier to mount the cutters but manufacturingis simplified. i

It is pointed out that the particular mounting permits the use of theelongated rollers as a bearing surface for the cutters. This is adecided advantage because it is obvious that an increased bearingsurface which prolongs the life of the bit and reduces replacements, isprovided. Further, the rollers carry the thrust against the cuttersduring the cutting operation, and it is obvious that this increasedsurface makes for smoother cutting. Also the provision of the rollerspermits the drill to be'eifectively used in drillingin hard formationsbecause of increased strength and durability which is capable ofwithstanding the increased jar produced by such drilling.

What'I claim. and desire to secure by Letters Patent is:

1. A drill bit including, a pair of complementary members ofsemi-circular cross section arranged to fit together to form the bitbody and having an axial bore when so assembled, semicircular flanges atthe upper and lower ends of the sections and arranged to form annularflanges at opposite ends of the axial bore when the sections are fittedtogether, a connecting sleeve having annular grooved heads at its upperand lower ends for engaging the flanges to hold the sections together,one of said heads being detachable and screw-threaded to the contiguousend portion of said sleeve, a cutter axle at the lower end of eachsection, and a rotatable cutter on each axle.

2. A drill bit including, a pair of complementary semi-circular sectionsarranged to fit together to form the bit body and having an axial borewhen so assembled, semi-circular flanges at the upper and lower ends ofthe sections and arranged to form annular flanges when the sections arefitted together, a connecting sleeve having annular grooved heads at itsupper and lower ends for engaging the flanges to hold the sectionstogether, acutter axle arranged to be fastened to the lower end of eachsection, a rotatable cutter arranged to be mounted on each axle, andsecuring means for said axle and cutter comprising a recess in the bodysection in which the axle is seated at one end, an annularly shoulderedrecess in the cutter, a series of rollers in said recess of the cutter,and a securing pin inserted through an axial bore in the axle and anopening provided in said body section, said pin having a headed endportion co-operating with said series of rollers to retain the cutter onthe axle and the opposite end portion of said pin being fixedly securedto said body section.

3. In a drill bit of the character described, a

body section, a rotatable cutter, an axle member having an annularflange abutting the face or said body section and an end portion fitte'din a recess provided therefore in said body section, sa d axle memberhaving a reduced opposite end portion providing a roller race with anannular shoulder, said cutter having an annularly shouldered 'recesstherein, a series of rollers in said recess of the cutter andworkingupon the reduced portion of said axle-member, and a retaining pininserted in an axial bore of the axle member and an alined openingprovided therefore in the body section, said pin having a head at oneend engageable with said rollers, the annular shoulder in the cutterrecess being engageable with the opposite ends ofthe rollers, and theopposite end portion of said pin being secured to said body section.

4. In a drill bit of -the character described, a

body section, said' body section having a recess in the face thereof, anaxle member having an end portion fittedin said recess and an adja--cent external annular shoulder abutting. the face of said body section,the outer end portion of said axle member being reduced in diameter withan annular thrust shoulder at the inner end of said reduced portion ofthe axle member, said axle member having an axial bore and the bodysection an alined opening, a rotatable cutter having anannularlyshouldered recess therein, a series of rollers in said annularlyshouldered recess of the cutter and working upon the reduced portion ofsaid axle member, and a retaining pin inserted in the bore of saidaxle'member and the alined opening of said body section, said pin havinga head on one end engaging the adjacent end of the series of rollers insaid cutter, the other end of the series of rollers engaging theshoulder on the cutter, and the opposite end portion of said pin beingwelded to said body section.

FERI A. THAI-IELD.

